Trailer coupler



Aug. 24, 1937. R, F KUNS y 2,090,891

TRAILER CUPLER Aug. 10. 1935' Patented Aug. 24, 1937 i' UNITED STATES PATENT* ori-"icl:

7 Claims.

The invention relates to means particularly adapted for use in making a safe and satisfactory double releasable coupling connection between a trailer or a semi-trailer and a passenger automobile.

Heretofore, users of two wheel trailers, intended to be connected to the rear of a truck, tractor or passenger motor vehicle, have utilized a coupler having contact with the rear of the tow 104 or passenger motor vehicle and rearwardly of the rear axle of said tow vehicle. Sometimes it has been necessary to remove the spare tire, sp-are tire holder, trunk and other apparatus from the rear of the tow vehicle, or replace these acces- 15 sories at a higher elevation or install new front fenders. having fender wells in order to carry the spare tire at the forward part of the tow vehicle to permit connection oi the tow bar of the trailer with the tow vehicle at its rear.

20 Also, it is well known that it is advantageous to distribute the weight on the tow bar of the semi-trailer and its load forward of the rear axle of the tow vehicle, rather than to distribute all or a greater portion of this weight rearward 25 of the rear axle. It is, also, generally known that if the weight of the trailer and its load, supported by the tow car, is located at a point in the rear of or above the center of the rear axle of the tow car, that the same or greater vertical movements of the rear wheels of the tow vehicle are imparted to the front end of the trailer. More over, the downward pressure of the weight of the tow bar, or front end of the trailer, has a tendency to lift the forward end of the to'w ve- 35 hicle free from the roadway which results in broken front springs, rapid tire wear and in steering of the tow car being difficult and dangerous. This same unsatisfactory distribution of weight also results in overloading the rear axle. When 40 the trailer or semi-trailer is coupled to the rear of the conventional passenger chassis it results in a very rough ride for passengers in the trailer. The pivoting action .between the trailer chassis and the tow car chassis being to the rear of the 5 rear axle of the tow car results in the rear of the trailer contacting the roadway when crossing curbs and gutters, owing to the greatly multiplied vertical movements of the rear wheels of the tow car and thereby resulting in damage to the 50 trailer.

` For these reasons, it is a desirable feature of trailer couplers that the weight and downwardi pressure of the front of the trailer or semi-trailer and its load be applied and distributed to all 55 wheels of the tow vehicle, as by having the forward end or ends of the trailer tow bar connected or coupled forwardly of the center of the rear axle of the tow vehicle. p

Therefore, the general object of the invention is to? provide simple, practical and efficient means adapted for utilization in connecting a trailer to a tow or passenger car at two points forward of and substantially in horizontal alignment with the rear axle of said tow car and which means can be utilized without changingthe fundamental design of the automobile, or removing and replacing accessories, such as trunks, spare tire holders, spare tires and bumper of the tow car.

Other objects of the invention are to provide a double point pivotal connection of said trailer with said tow Car which will permit the trailer wheels to follow closely the tracks of the tow car; and to provide means to distribute the weight or downward pressure of the front part of the trailer and its load at a point forward of the rear axle of the tow car, whereby the four wheels of the tow car support said weight and the normal vertical movements of the front part of said trailer and saidtow bar is considerably less than the vertical movements of the rear axle and wheels and front axle and front wheels of said tow car. y

Otherobjects of the invention will be apparent by reference to the drawing, the hereinafter de scription, and the claims.

' The invention consists in providing mean which are Icapable of being utilized for coupling the trailer to the tow carat two points forward of the rear axle of said tow car and substantially in horizontal alignment therewith, and also in connecting saidfmeans to the trailer by utilization of pivotal mechanism adapted to pivot vertically and horizontally, and in provision oi a swiveling mechanism which 'compensates for irregularities inroadsurfaces and transmits the weight of the lforward endv of said trailer to two points forward of the rear axle of said tow car and at each sideof said tow car at which the trailer is-connected with the tow car.

' Tliiinvention, also, consists in the combination of the elements, arrangement of the parts and in the details of the construction, as hereinafter claimed.

In the drawing: ,A

Fig. 1 is aplan view of the invention shown in.- cor'porated witha tow car partlybroken away;

Fig. 2 is a side elevational View of the same; I Fig;4 3 is a side elevationalview o-fl the'I drag link, shown partly' broken away;

Fig. 4 is a section taken on a line corresponding to 4--4 in Fig. 1;

Fig. 5 is a section taken on a line corresponding to 5-5 in Fig. 1; 5 Fig. 6 is a section taken on a line corresponding to 6 6 in Fig. 8; v

Fig. 7 is a section taken on a line corresponding to 1 1 in Fig, l, with parts broken away;

Fig. 8 is a section taken on a line correspondloing to 8 8 in Fig. 7, showing parts broken away; and

Fig. 9 is a plan View of the cross arm connector and cross arm, Showing parts broken away.

The preferred construction of the invention is l5 exemplified with the tow or passenger car I which has the usual bumper 2 connected with the rear ends 3 and 4 of theframe 5 of the car I. The trunk 2 and the 4spare tire'2" are connected, as usual, to the rear end 0f the car I.

The usual bolt, which is used to secure the end 6, of the bumper 2, to the end 4, of the frame 5, is discarded and the threaded shank 1 is screwed in the usual holein the end 4 of the frame. The shank `1 is integrally formed with the boss 8 which has integrally'formed with its inner end the ball 9 received through the hole III, in the sleeve II, of the drag link I2. The sleeve II has therein the hole `II whose side walls extend at right angles with the side walls 30 of the hole I0 and has screwed therein the retaner screws I3 and I4 whose inner ends are cupped and have received in contact therewith the ball 9. The end I5, of the tire rod I6, is threaded in the hole II' and to the inner end I1 of the sleeve II. The other end I8, of the tie rod I6, has threaded thereto the sleeve I9 having pivoted therein a ball (not shown and similar to the ball 9) which has integrally formed therewith the boss having integrally formed l therewith a threaded shank which is fixed in the end 2| of the cross bar 22. Each of the inner ends of the sleeves II and I9 have the slots I9 therein and have integrally connected therein the spaced apart ears I9" through which is received the bolt I9- for the purpose of xing the 'inner ends of the sleeves to the ends of the tie rod I6. The ends 2I and 23, of the cross bar 22, are pivotally connected, as by the vertical bolts or king pins 24, to the rear ends of the Yarms 25 and 26 which areadapted to' be pivoted laterally ofthetowcarI. y"

The trailer 21 has xed to its frontend 28 a tow bar 29 which comprises the spaced apart frame members 30 and 3l, respectively, having fixed thereto, as by the bolts 32 Vand 33, the upper and lower plates 34 and 35 of the rectangular connector or yoke 36. Extending through the rectangular yoke 36 is the cross bar 22 having received through its middle portion the horizontal bolt or pin 31 wherebythe cross bar is'adapted to be pivoted vertically while resisting any rotation about its axial line.

Each of the arms 25 and 26 comprise the channel plates 38 and 39 having their frontends xed to the rear ends of the rods 40 and 4I, as by the bolts 42. The rods 40 and 4I have their inner ends 43 and 44 bent `.inwardly and have therein the groove 45 adapted to be receivedv in the slots 46 of the vertical plates 41 andAnhaving their lower ends bent inwardly and xed, yas bythe rivets 49, to the outer edges of the running boards 50 and 5I of the tow car I. u

Pivotally connected, to the plates 41 and 48, as by the bolts 52,.are the hooks 53 and 54 whose 75 curved ends 55 'are adapted to'l be received over the ends 43 and 44 of the rods 40 and 4 I for the' purpose of preventing the forward ends of the arms 25 and 26 from being removed, as by vibrations of the tow car I, from the slots 46 in the vertical plates 41 and 48 during travel of the tow car I and the trailer 21. The channel members 38 and 39, of the arms 25 and 26, extend horizontally and in alignment with the rear axle, of the tow car I, on which the rear wheels 56 are rotatably mounted.

The forward ends 43 and 44, of the arms 25 and 26, are connected a relatively great distance lforward of the rear axle of the car I, whereby relatively small movements are imparted vertically to the front end 28, of the semi-trailer 21, when either the front wheels or the rear wheels of the tow car move vertically over an obstruction or depression in the highway. The drag link I2 is connected with the end 4 of the frame 5 which is adjacent the side 51, of the tow car I, and connected with the end 2|, of the cross bar 22, adjacent the side 58, of the car I, whereby side movement of the lcross bar 22, with respect. to the car I, is limited.

The king pins 24 are mounted in vertical positions, in the cross bar 22, and are maintained in vertical positions by the action of the bolt 31.' in the rectangular yoke 36 which prevents the,` bar 22 rotating about its axis, so that weight. of' the semi-trailer 21 is borne by the several members comprising 30, 3|, 33, 34, 36, 31 22, 24,l 25 and 26. The weight is transmitted' forwardly and is received by the tow car through the plates 41 and 48.

An advantage of the invention is that the load of the front end of the trailer is; supported by the two couplers on the running boards of the tow car whereby said weight of the semitrailer is received at points forward of the rear axleof the tow car, thereby providing a practical disposition of the load weight of the semi-trailer on four wheels of the tow car whereby the stability of the tow car is assured and normal steering of the tow car is unchanged.

Still another advantage of the invention is that the installation of the supporting blocks on the running boards of the tow car is simple and the attachment of these supporting blocks is the only change of the tow car necessary to connect the trailer, whereby the spare tire holder, spare tire, trunk and bumper remain in their original positions on the tow car.

Still another advantage of the invention is that the rigid construction of the various parts, particularly with reference to weight carrying adaptability of the pivotal mechanism and the forwardly extending arms in connection with the drag link permits easy swiveling of the mechanism and, also, the arms are retained in xed and adjusted position with respect to inward movements.

Still another advantage of the invention is that satisfactory and eflcient braking of the tow car is provided because the weight of the forward part of the trailer is distributed in a highly desirable manner on four wheels of the tow car.

Still another advantage of the invention is that the trailer may be connected to or disconnected from the tow car quickly and conveniently and the forwardly extending arms may be turned through an arc of 180 degrees to be disposed rearwardly of the tow car under the semitrailer front. Y Y

Still another advantage of the invention is that during ordinary travel, the vertical movements of the front or rear wheels of the tow car are not imparted to any great extent to the front of the trailer, because the front ends of the horizontal arms are connected between the front and rear axles of the tow car and at a point substantially in horizontal alignment with the rear axle of the tow car, whereby the vertical movements of the trailer being considerably reduced, when compared with the usual vertical movements imparted to a trailer attached to the rear end of the tractor, the trailer 21 rides with relative comfort to the occupants.

While I believe that the form of the invention illustrated in the drawing and referred to in the above description, as the preferred ernbodiment, is efficient and practicable, yet realizing that the conditions concurrent with the adoption of the device will necessarily vary, I desire to emphasize the fact that changes in the details may be resorted to, when required, without sacricing any of the advantages of the invention as defined in the claims. l

Various chan-ges may be made in the general form and arrangement of mechanical parts described without departing from the invention. Hence I do not limit myself to the precise details of the materials or the size and shape thereof as set forth, but consider myself at liberty to make such changes and alterations as fairly fall within the spirit and scope of the appended and final claims.

What I claim as new and desire to secure by Letters Patent is:

1. The combination with a tow vehicle and a trailer having a tow bar, of a horizontal cross bar pivotally connected with said tow bar, horizontal arms pivotally connected with the ends of said cross bar and extending forwardly and adapted to be pivoted laterally, means to limit the inward pivotal movement of said arms, and means to pivotally connect the forward ends of said arms with the sides of said tow vehicle forward of the rear axle of said tow vehicle, said horizontal arms being substantially in alignment with said rear axle of said tow vehicle.

2. The combination with a tow vehicle and a trailer having a tow bar, of a cross bar extending transversely of said tow vehicle and being pivotally connected with said tow bar, horizontal arms pivotally connected with the ends of said cross bar and extending forwardly and adapted to be pivoted laterally, means to limit the inward pivotal movement of said arms, and means to pivotally connect the forward ends of said arms with the sides of said tow vehicle forward of the rear axle of said tow vehicle, said arms being substantially in alignment with said rear axle.

3. The combination with a tow vehicle and a trailer having a tow bar, of a horizontal pivot pin, a horizontal cross bar pivotally connected with said horizontal pivot pin through said tow bar, vertical pivot pins connected with the ends of said cross bar, horizontal arms connected with the ends of said cross bar by said vertical pins and extending forwardly and adapted tobe pivoted laterally, means to limit the inward pivotal movement of said arms, and means to pivotally connect the forward ends of said arms with the sides of said tow vehicle forward of the rear axle of said tow vehicle, said horizontal arms being substantially in alignment with said rear axle of said tow vehicle.

4. The combination with a tow vehicle and a trailer having a tow bar, of a cross bar extending transversely of said tow vehicle and being pivotally connected with said tow bar', horizontal arms pivotally connected with the ends of said cross bar and extending forwardly and adapted to be pivoted laterally, and means to pivotally connect the forward ends of said arms with the sides of said tow vehicle forward of the rear axle of said tow vehicle, said arms being substantially in alignment with said rear axle.

5. 'I'he combination with a tow vehicle and a trailer having a tow bar, of a cross bar extending transversely of said tow vehicle and being pivotally connected with said tow bar, horizontal arms pivotally connected with the ends of said cross bar and extending forwardly and adapted to be pivoted laterally, and means to pivotally connect the forward ends; of said arms with the running boards of said tow vehicle forward of the rear axle of said tow vehicle, said arms being substantially in alignment with said rear axle.

6. The combination with a tow vehicle and a trailer having a tow bar, of a cross bar extending transversely of said tow vehicle and being pivotally connected with said tow bar, horizontal arms pivotally connected with the ends of said cross bar and extending forwardly and adapted to be pivoted laterally, and means to pivotally connect the forward ends of said arms with the running boards of said tow vehicle forward of the rear axle of said tow vehicle.

7. The combination with a tow vehicle having running boards intermediate its front and rear wheels, and a trailer, of a pair of arms, draw bar means connected with said trailer, the rear ends of said arms being pivoted to said means and adapted tol swing laterally, means tol connect the front ends of said arms with said running boards, and means to limit the lateral movements of said arms.

RAY F. KUNS. 

